In general, as the automotive industry develops, problems of condensation in headlamps, rear lamps, fog lights and the like during transportation and storage of automobiles continuously occur, which causes increased industrial loss.
In an automotive lamp, when temperature difference between inside and outside parts is big in a high humidity environment such as in the rain, moisture inside the lamp condenses so that fine water drops occur on the inner surface of the lens to induce fogging. A light scattering phenomenon resulting therefrom becomes a big obstacle to safely driving cars.
Generally, in order to solve the problem, a method of mounting an anti-fog coating agent and a bentonite-based moisture absorbent in a housing of the lamp and using them has been used in the current automotive industry. However, the anti-fog coating agent undergoes deterioration such as whitening or a flowing phenomenon by outdoor UV, temperature, humidity and the like, and in this case, an automobile lamp module should be replaced. In addition, after absorbing a certain amount of moisture, a general bentonite-based moisture absorbent re-releases moisture in a high temperature and low humidity environment during operation of the lamp, thereby causing condensation on the inner surface of the lamp lens.
Due to the above problems caused by the use of the conventional anti-fog coating agent and the bentonite-based moisture absorbent, replacement costs for the automobile lamp module are incurred, and functional quality and consumer quality deteriorate. Accordingly, in order to improve the condensation problem of the conventional moisture absorbent, a moisture absorbent having a new function which may minimize moisture release or absorb moisture even in a high temperature and low humidity driving environment is demanded.